An acute depression in local perfusion pressure and blood flow is a direct indicator of an increased risk of ischemic damage. Direct, continuous measurement of local blood and other fluidic pressures and flows can therefore be critical in acute situations such as trauma and surgery, but is currently difficult or impossible, particularly in the case of central nervous system (CNS) pressures and flows. Direct, continuous measurement of intracranial pressure (ICP) is currently only available via invasive techniques, while intracranial blood flows are only available indirectly via measurements of velocity using Doppler ultrasound. Intraocular pressure (ICP) and blood flow can be measured noninvasively, but only with the eye open and for short durations.
It would be desirable to have an apparatus to overcome the above deficiencies.